From 90 to 92 I quested normally get them garrison quests done, then fly around picking up all the treasure in shadowmoon after that. I flew to Bloodmaul slag mines (horde area) used Elixir of the rapid mind. (using the log in and out method) Within a few hrs I'm 100.

From 100 I do a few quests in Highmountain and get the bodyguard and grind to 110 killing elites in highmountain. I dont mind the grind, its easily and no lag, and with my pc at the moment that is the best bet